Electric alarm



(No Model.)

H. F. KOLBE.

ELECTRIC ALARM. No. 496,690. Patented May 2, 1893.

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HENRY F. KOLBE, OF DETROIT, MICHIGAN.

ELECTRIC ALARM.

SPECIFICATIOZI forming part of Letters Patent No. 496,690, dated May 2, 1893.

Application filed November 14, 1892. Serial No. 451,931. (No model.)

To all whom it may concern:

Be it known that I, HENRY F. KOLBE, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electric Alarms, of which the following is a specification,reference being had therein to the accompanying drawing.

My invention particularly relates to a locking mechanism for the bell hammer which. is especially applicable to bells used in locomotive cabs and other places where subject to constant jar and prevents the sounding of the bell excepting when actuated by its magnet.

The invention consists, first, in the means employed for automatically locking and unlocking the armature,and,further, in the peculiar construction, arrangement and combi-- nation of parts more fully hereinafter described.

In the drawing, I have shown a vertical longitudinal section through a bell to which my improvement is attached showing in dia gram its actuating electric circuit.

A is a suitable box or casing inclosing the operating parts.

B is a metallic frame to which the various parts are attached having standards 0 projecting upward through the casing and forming the supports for the bells D. In the drawing I have shown two bells with the striking hammer between, but where desired a single bell may be used.

E is an electro-magnet secured to the frame B. F is a vibratory armature pivoted at G and carrying a bell hammer 'H.

I is an adjustable retracting spring for the armature.

J is a current breaker consisting of a contact spring K upon the armature and adj ustable contact screw K in the insulated post K secured to the frame; the parts so far described all being of usual and known construction, and forming what is commonly known as a continuous ringing electric bell adapted if placed in a suitable electric circuit such as shown atL to sound whenever the circuit is closed.

To hold the armature F from vibrating except when actuated by the magnet E, I apply an automatic locking latch which may be of any suitable construction but preferably that shown in the drawing in which M is an arm secured to armature F and provided with an aperture M.

N is a latch arm pi'votally secured at N to the frame and extending over the arm M.

O is a pin on the under sideof the latch arm N, adapted to enter aperture M and hold tension carrying a suitable armature, or the whole arm being formed of light iron.

Having now described the construction of my bell I will explain its operation when used on a railroad train: The bell may be secured in any convenient place, in the cab of the lo comotive, and the wires R and R of the electric circuit L extend the entire length of the train being provided with any suitable means of connection between the dilferent cars. In each car is arranged a push button S adapted when operated to complete the circuit. Supposing that the ccnductor now wishes to sig nal the engineer he can do so from any point on the train by pressing one of the push buttons which will complete the electric circuit thereby energizing both the electro-magnets E and P. As the armature of the latter magnet, however, is much lighter than the vibratory armature F of the magnet E, it will naturally move first, thus unlocking the armature F by disengaging the latch arm N from the arm M.

To prevent any possibility of binding by the movement of the armature F before the disengagement of the latch I preferably make the aperture M somewhat larger than the pin 0 allowing thereby a little lost motion giving ample time for the latch arm N to move. As soon as the circuit is again opened the latch arm N will be free to re-engage with the arm M and again lock the armature.

It will be noticed that as the releasing magnet is in a separate branch of the electric circuit from that containing the actuating magnet and current-breaker; it is not affected by the interruption of the current and will hold the latch out of engagement with its armature until the main circuit is again opened. This is advantageous as it prevents the latch from interfering with the free movement of the armature, as there would be danger of its doing if the two magnets were in series with each other. At the same time it forms a positive lock for the bell hammer which is as effectual as where a permanently closed circuit is used.

What I claim as my invention is- 1. In an electric alarm, the combination with the vibratory armature and its actuating devices, of an automatic locking latch for said armature,a releasing magnet and a normally open electric circuit having two branches, one

HENRY F. KOLBE. Witnesses:

M. B. ODOGHERTY, N. L. LINDoP. 

